This section is intended to provide a background or context to the invention that is, inter alia, recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Fuel cells are rapidly becoming an important component in the energy industry; but currently costly Pt catalyst is typically a required component of the fuel cell. To make fuel cells commercial competitive at reasonable cost, the amount of Pt used in the fuel cell should be reduced by a factor of 4 to 5. Further, catalyst stability should be improved for longer term operation of the fuel cell. Pt based alloys embedded in high surface area carbon substrates have been developed that improve catalyst performance by a factor of two. However, these efforts have not increased catalyst stability, and have not reduced the total loading of Pt in the fuel cell stacks to acceptable levels. Additionally, the substantial overpotential for oxygen reduction reaction (“ORR”) at practical operating current densities still causes a reduction of thermal efficiency. These efforts have resulted in systems that are well below thermodynamic limits (typically to about 43% at 0.7 V versus the theoretical thermal efficiency of 83% at the reversible potential for the ORR). Also, the dissolution and/or loss of the Pt surface area in the fuel cell cathode should be reduced for practical application of fuel cells.